Date of Award
Spring 2023
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Interdepartmental Neuroscience Program
First Advisor
Small, Dana
Abstract
The 21st century rise in obesity coincides with the increased prevalence of palatable, energy-dense foods and the ubiquitous cues signaling their availability. Food cue reactivity refers to the responses to these cues – such as increased salivation, brain activity, or the cognitive experience of craving – that become conditioned through prior consumption. Food cue reactivity is highly predictive of food intake and body weight; however, the mechanisms underlying risk are poorly understood. The overarching goal of this dissertation is to investigate factors that influence food cue reactivity in humans. Over three experiments, I examined factors related to the individual or to the food itself. First, it is well understood that gut-brain signals generated during nutrient digestion are the primary reinforcers behind the conditioning of environmental signals into food-predictive cues. I therefore tested the roles of both nutritional factors including energy density and macronutrient composition and individual factors such as food liking and perceived healthiness in the subjective valuation of food (Chapters 2 and 3). This work revealed that individuals with healthy weight, but not with obesity, find foods containing roughly equal amounts of fat and carbohydrate in combination more reinforcing than foods with predominantly fat or carbohydrate in isolation (Chapter 3). Second, given that prior work has implicated the olfactory system in obesity risk, I examined whether central olfactory coding impacts reactivity to food odors (Chapters 4 and 5). I showed that the ability to decode odor quality from distributed brain patterns captured with functional magnetic resonance imaging correlates with cue-potentiated feeding in the sated state (Chapter 4). Finally, mental imagery involves the reactivation of sensory circuits and is thought to intensify craving. Since previous research has shown that odor but not visual imagery ability varies widely across the population and positively correlates with body mass index, I investigated the specific contributions of odor imagery ability to food cue reactivity. Across multiple measures, I found that better odor imagery ability predicts larger changes in adiposity via elevated cue-induced craving and intake (Chapter 5). The studies in this dissertation collectively support a model by which humans are generally more cue reactive to foods rich in added fat and sugar, with olfactory coding and mental imagery influencing individual susceptibility for overeating and weight gain.
Recommended Citation
Perszyk, Emily Elizabeth, "Investigating Factors That Influence Food Cue Reactivity in Humans" (2023). Yale Graduate School of Arts and Sciences Dissertations. 870.
https://elischolar.library.yale.edu/gsas_dissertations/870
